20KHNR steel is used: for the manufacture of gears, shaft gears, worms, dog clutch, rollers, fingers, bushings and other major loaded parts operating under conditions of shock loads.

Note

Structural steel high-quality chrome-Nickel with boron.

Standards

Name	Code	Standards
Sheets and strips	В23	GOST 103-2006
Bars and shapes	В22	GOST 1133-71, GOST 8319.0-75, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Bars and shapes	В32	GOST 4543-71, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-1-2118-77, TU 14-11-245-88, TU 14-136-367-2008
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90, TU 14-1-4944-90

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	B	Ti
GOST 4543-71	0.16-0.23	≤0.035	≤0.035	0.6-0.9	0.7-1.1	0.17-0.37	0.8-1.1	Rest	≤0.3	≤0.05	0.001-0.005	≤0.06

Fe is the basis.
According to GOST 4543-71 the content in high-quality steel is regulated: P≤0,025%; S≤0.025%; Сu≤0.30%; in high-grade steel: P≤0,025%; S≤0.015%; Сu≤0.25%.

Mechanical properties

Section, mm	t отпуска, °C	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
15-25	-	1370	1420	14	60	1060	-	-
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
≤25	-	1370	1420	14	60	1060	418	-
Quenching in oil from 860 °C to + vacation, hladanie in oil
-	200	1220	1520	10	54	481	-	47
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
25-75	-	970	1060	15	60	1060	-	-
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
100-150	-	830	1000	16	-	961	286	-
Quenching in oil from 860 °C to + vacation, hladanie in oil
-	300	1200	1400	-	-	481	-	46
Normalizing at 930-950 °C, air cooling + tempering in oil with 780-830 °C + vacation at 200 °C, cooling in air or in oil
≤15	-	980	1180	10	50	863	-	-
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
25-50	-	1110	1200	-	62	1442	340	-
Quenching in oil from 860 °C to + vacation, hladanie in oil
-	400	1180	1250	11	57	677	-	43
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
50-75	-	970	1060	15	60	1060	302	-
Quenching in oil from 860 °C to + vacation, hladanie in oil
-	500	880	980	14	64	1246	-	34
Normalizing at 930 °C, air cooling + tempering in oil from 840 °C to + vacation at 200 °C, air cooling
75-100	-	920	1000	15	60	1245	302	-
Quenching in oil from 860 °C to + vacation, hladanie in oil
-	600	740	780	16	65	1687	-	28

Description mechanical marks

Name	Description
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number
HRC	Rockwell hardness (indenter diamond spheroconical)

Technological properties

Name	The value
Weldability	RDS. Recommended heating and subsequent heat treatment.
Склонность к отпускной хрупкости	inclined
The temperature of forging	Start - 1150 °C, the end - of 800 °C.
Flock-sensitive sensitivity	sensitive

Steel 20KHNR

Designation

Description